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RE: ANNOUNCEMENT: RDFStyles: alternative to XSLT for RDF

From: Leo Sauermann <leo@gnowsis.com>
Date: Wed, 29 Oct 2003 10:38:14 +0100
To: "'Emmanuel Pietriga'" <epietriga@yahoo.fr>
Cc: <www-rdf-interest@w3.org>
Message-ID: <000a01c39e00$61714e30$0501a8c0@ZION>

> > normally:
> > SELECT ?x FROM (?x rdf:type foaf:Person)
> > 
> > 
> > I assumed to use "." as the context node abbrevation, this is also
> > standard in filesystems and XPath syntax, so commonly used.
> > 
> I agree with this notation choice.
> 
> > The easy syntax by me would return all "?" missing things.
> > 
> > There could be more than one ? which could be merged
> > 
> What do you mean by merged?

(? rdf:type foaf:Person), (? rdf:type dc:Document)

should return all persons and document resources in a single list.
 
> 
> 
> > to do ANDs and ORs you could use named things:
> > (?a rdf:type foaf:Person) AND (?a foaf:knowsAbout ?)
> > 
> 
> how do you interpret the expression above w.r.t the context node?

context is not evaluated, these search in all triples of the graph.

like XPath : "//person/"


> the problem is not just addressing RDFPath expressions, but also 
> instructions associated with these expressions. What I meant by 
> select="*" was not just how to have something equivalent in 
> rdfpath, but 
> what should be considered as equivalent, given the fact that 
> we have a 
> potentially cyclic graph and not a tree?


no problem, Jena does show this very good:
A graph consists of triples, and those are counted. All queries work on
the triples. If you do a select "*" you get all triples, which is ok, if
you need it and have a limited model.

greetings
Leo
www.gnowsis.com
Received on Wednesday, 29 October 2003 04:33:09 GMT

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